Impact of long-term home parenteral nutrition on bone metabolism and mineral density: a case report

Objective: To analyze the impact of home parenteral nutrition (HPN) on bone metab- olism and bone mineral density (BMD). Methods: The biochemical markers bone metabolism and BMD (with dual-energy x-ray absorp- tiometry) were assessed before starting HPN and during 42 months of follow-up in a patient with intestinal pseudo-obstruction who apparently had no other factors interfering with bone metabo- lism. Results: Before starting HPN, a hyperkinetic bone turnover and a negative calcium balance were present, and BMD T-score (standard deviations below mean BMD of healthy young subjects) was - 3.9 at spine and -2.9 at femur. During the follow-up, bone turnover normalized and BMD signifi- cantly decreased at femoral neck and remained stable at spine. Regression analysis showed that duration of HPN was associated negatively with serum osteocalcin and urinary pyridinolines, and with serum parathyroid hormone (PTH). Conclusions: The results agree with the hypothesis of the development of a low bone turnover and a decreased bone sensitivity to the PTH bone-building action during long-term HPN. (Nutritional Therapy & Metabolism 2008; 26: 86-92)